The invention relates to a pneumatic recuperator mechanism for a gun barrel.
Such recoil brakes or recuperator mechanisms are illustrated in FIG. 879, page 377 of the "Rheinmetall Handbook on Weaponry, second English edition, published by Brenners Druckerei Breidenstein GmbH., Frankfurt am Main, West-Germany. Such recuperator mechanisms consist of a displacement cylinder and a storage cylinder which encloses the displacement cylinder. Within the displacement cylinder a piston and piston rod is slidably mounted, which when a shot is fired from a gun barrel transports as a result of the recoiling gun barrel gas from the displacement cylinder via a valve opening into the larger dimensioned recuperator cylinder. The displacement cylinder is for purposes of rapidly evacuating it provided with a check valve closing the outer cover, mounted at the end of the displacement cylinder which is not sealed off by the piston. The counter recoil is effected by the decompression of the compressed gases at the exit pressure. The counter recoil is throttled via a constant throttle. For purposes of sealing the axially slidable piston and piston rod there serve ring seals, which must be greased by means of pressure loaded grease lubricating chambers. These grease lubricating chambers require, however, an additional space for the oil, respectively grease volume, which must be refilled in relatively short periods of waiting time, whereby they can occur disadvantageous disruptions not only during a state of rest but also during firing operations. For controlling the ready to operate condition it is further necessary to indicate the pressurized condition of the lubricant. As result of the relatively small piston surface of the counter recoil piston there is required a high pressure level for the counter recoil, whereby the wall thickness of the arrangement must be increased which makes for a heavy recuperator mechanism and as a result of the complex construction a high finishing input is required.
In contra-distinction thereto the invention has as an object to avoid the afore-described drawbacks and to improve the recuperator mechanism of the afore-described type in such a way that with equal predetermined constructional cross section a simply constructed and thereby lighter recuperator mechanism with a higher operative readiness having less delays is provided.
The pneumatic recuperator mechanism has, according to the invention, the decisive advantage that it only requires one cylinder for the displacement chamber and the storage chamber. With a cross section of the same size as compared to that of the known recuperator cylinder there results a storage chamber, which corresponds to the displacement chamber insofar as the inner diameter is concerned, and only requires a comparatively low pressure level. Thereby there results jointly with the slidable arrangement of the valve within the single cylinder a simple and particularly weight-saving construction, whereby for example in an advantageous manner the weight-savings can be used for an increased armor protection.
A high operative readiness with less delays is achieved with the recuperator cylinder in such a way that the recuperator piston and valve contain on their outer surfaces which slide along the cylindrical inner walls, in addition to exchangeable, friction-poor guide elements also wear and delay-free sealing elements. The valve is during recoil in the cross piece region tightly sealed in such a way that in the exterior region by a delay-free seal along a ring surface of smaller diameter with a relatively high specific pressure relative to the socket, the counter recoil velocity is exclusively controlled via a throttle valve with constant or variable cross section.
By using an indicating arrangement for indicating the pressure of the pneumatic operating medium there is centrally advantageously readable the operative condition of the recuperator mechanism.
According to a further feature of the invention the recuperator piston is offset relative to the valve, whereby a reduction of the cylinder length and thereby a further weight-saving of the recuperator cylinder is achieved.
The invention is hereinafter described in conjunction with drawings in which preponderantly there has been omitted constructional details not relevant to the invention and which illustrate the preferred embodiments;